Magnetic blow-out for make-and-break devices.



No. 887,737. PATENTED MAY 12, 1908.

s. D. FIELD.

MAGNETIC BLOW-OUT FOR MAKE AEED BREAK DEVICES v APPLICATION FILED DEC.12,1907.

' To all whom it may concern.

STEPHEN DUDLEY FIELD, OF STOOKBRIDGE, MASSACHUSETTS, ASSIGNOR TO PITTSFIEL SPARK COIL COMPANY, OF DALTON,

MASSACHUSETTS, A CORPORATION.

MAGNETIC BLOW-113???? E9331 MAKE-AND-BREAK DEVICES.

Be it known that I, STEPHEN DUDLEY FIELD, a citizen of the United States of Amer- 1.0a, residing at Eltochbridge, in the county of Berkshire and State of Massachusetts, have invented new and. useful Improvements in Megnetic Blow-Outs for Malcemndfireek Devices, of which the following is e. specificstion.

This invention relates to improvements in electribal make and break contact devices, the object of the invention being to provide means for instantaneously extinguishing the spark that occurs at the make and break con tact points when the primary circuit of an induction. coil is broken. y

The invention set forth in this application is an improvement on the invention shown and descrihed in my application for Letters Patent of the United States for improvement In ltebounding ignition and spacer device .for explosive engines filed November 29,

v thep 190? under Serial No. 402,988. In the operotion of an ordinary induction coil in which a vibrator is employed, the core of the same is so arranged with relation tothe vibrator (which affects the making and breaking of the primary circuit) thatthe lines of force from. the core will assist the condenser in quickly extinguishing the s ark at the con tact oints at the instant o the breakin of the strength of the induced current in the secondar winding is greater in proportion to the a ruptness ofvthe extinguxshmentloi the are attl1e.n1ai c and breakcontaet points of the primary. If the arc is permitted to he drawn out or lengthened bfifore it is broken, that is to gradually die out. little, if any, inductive cfleot would be produced in the sec ondary winding of the coil, and consequentiy there would notbe produced, a sufficiently large spark at the spark pl ugto ignite the vaporous charge in the Cylinder of the engine.

the ma. e and break device being located at a'distance from the-induction coil, I have foundit necessary to provide some means to instantaneously and thoroughly extinguish the spark when the primary circuit is broken at the contact )oints and in order tOflCCOIIk plish this result satisfactorily, I envelop the contact poiz'its in a strong magnetic field, this field being produced, preferably, by

Specification of Letters Patent.

Application filled December i2, 19M. Seriai No. 406,147.

inner-y circuit, it being well knownt st 'In'm prior application above referred to,

Patented Kay 12, 1908.

"means of a permanent magnet with the north and south poles located between the two poles of the magnet, and 'oonsequentl when it break occurs in the primary circuit at the contact points, the spark, instead of being drawn out or gradually'reducedi] is ed instantaneously and thoroughl extinguis by means of the magnetic fie d, assisted, of course, by the usual condenser which is connected across the contact terminals in the usual manner.

In the drawings forming a part of this applicetion,-Figure i is a side elevation of my improvement showing the location of the make and break device and the sporkga-p, and the north and south poles; of a permanent magnet 0; 2 is s sectional view on the line 2-2, Fig. 1.

Referring to these drawings in detail, a designates the ordinary cam-shaft or some equivalent moving part of an internal comhustion engine, that is employedto operate the inehe and break mechanism and which opens and closes the circuit in the primary windings of an induction coil. These terminals are indicated by the wires 6 and c.- designates a gear mounted on the cm or o-t er shaft a which is arranged to mesh with the main shaft of the internal combustion engine. a designates e bracket that is secured to the permanent magnet j; which bracket sup rtethe face-plate g on which are mounte the cam devices it. The magnet employed is of the horseshoe type. 5 'These cam devices are arranged so as to strike the end i of the arm of the contact lever during their rotary movements;

k 'designatesss a whole the'balance contact leverwhich is pivotally mounted on one pole of the-permanent magnetf at the point m, The balanced or weighted portion of this lever is indicated atjn. Secured to the other pole of the permanent n: t fis a pole piece 0 sof iron and on w 'ch is secured one of the contact inta of the make and, break device that-1s designated by the letter. p. The other contactpoint is designated-by the letter q and is carried on the end of a leaf spring 1'. s, designates a bracket that is also secured to the permanent ma met-f for rigidly securing one end. of the lent-springs t and. u and also the arm 1: which is used to place the springs normally in a the horseshoe type, and Fig. v

state of stress. The position of the parts, as

snown in Fig. l, is at the moment of se tion of the contact points p and q, an the pin -20 pressing the springs away from the curved end a: of the arm "0, the free end or the spring 25 being also at this instant away from tgie pin 1 The above described parts and their tunenand operation have already been fully ribed and set forth in my copending app ation,- and further reference to them ms unnecessary in this application.

By locating the balance contact lever is on one pole of the permanent ma net f and the contact point p on the other po e by means of the soft iron pole-piece 0, and in the plane of the )ermanent magnet, the make and break mecnanism will therefore operate in the field or air-ga of the permanent magnet and be complete y enveloped by the lines of force, which at this point are very dense.

l Vhen a break occurs in the primary cir, cuit at the contact points p and the spark that follows such break will e instantaneously extinguished or blown out by reason of the lines of force in this field or airap, as well known, resulting in the sudden emagnetization of the core of the induction coil, whereby the induced or spark current is correspondingly strong, by reason of the greater inductive efiect produced therein.

The ordinary spark-coil, as employed for internal combustion engines, is provided with a condenser to assist in dema 'netizing the core of the coil at the instant oflareaking of the contact points in the primary circuits; butii this spark is not instantly extin uished, the induction in the secondary win ing will be very much less; therefore, in order to bring about the'same result when the make and break devices are located at a distance from the induction coil, that is out of the range of the field of the core, I employ the permanent magnet f to etlfect the same results, that is to blow out or instantaneously extinguish the spark when a break occurs in the primary circuit or" the coil.

It should be stated that the balance lever is and the arm are composed of magnetic materia-l, preferably soft iron or mild steel so that the lines of force will be very much confined or concentrated between the north and south poles of the magnet, and in the region of thecontact points 1) and g of the make .and break device.

ara-l the magnet poles,

l l l l l l whereby when the contacts are separated an arc will be extinguished as described.

As an improvement in means for extinguishing the electric arc at the make and break contacts of an ignition system, in com bination, a permanent magnet, the contacts being arranged in the air gap of the magnet, one of said contacts comprising a contact arm and forming a portion of the magnetic circuit, means for operating one of the contacts, whereby when the contacts are separated an electric are between said contacts may be prevented.

3. In combination, a permanent magnet, the poles of which are arranged in 0 )position to each other, a make and breakrievice arranged within the airgap oi the magnet, said make and break device forming a portion of the magnetic circuit.

a. In combination, a magnet, the poles oi which are arranged in a jupctaposed position, a make and break mechanism located within the magnetic influence of the poles, as described, and forming a portion of the magnetic circuit of the magnet.

In combination, a magnet, a contact element mounted thereon, a movable member for enga ing the contact element and pro viding a path for the magnetic flux, whereby any arc formed between the contact and movable element may be extinguished.

6. In combination, make and break devices, a permanent magnet for producing a permanent magnetic flux for envclo ing said devices, one of the members of sai devices constitutin a portion of the magnetic cir cuit, where )y the reluctance of the circuit is decreased, and at the make and break devices the formation of an arc is prevented.

7. In combination, a permanent magnet,

the poles of which are arranged in opposition to each other, a make and break element pivotally supported in proximity to one pole of the magnet and having its free or contact end arranged in proximity to the other pole of the magnet, whereby said element constitutes a portion oi the magnetic circuit, and whereby the reluctance of the circuit is decreased, as described.

8. In a magnetic blow-out for ignition systems, in combination, a make and break device, means for enveloping said device with a permanent magnetic lield oi force, said device constituting. a part of the magnetic circult.

STEPHEN DUDLEY FIELD. l/l'itncsses:

F. F. CoRLrss, GEO. SEYMOUR.

whereby when a break occurs. 

